Switch mechanism



Feb. 5, 1929. 1,700,875

r v. I... BELL SWITCH MECHANISM Filed Aug. 13, 1927 INVENTOR VictorLBell BY z :zToRNEY Patented Feb.'5, 1929.

UNITED STATES PATENT OFFICE 'V'ICTOR I. BELL, OI EDGE'WOOD, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SWITCH MECHANISM.

Application filed August 13, 1887. Serial No. 212,668.

My invention relates to switch mechanisms, and particularly to pilot switches such as are used on theater lighting switchboards for shunting a pre-selected lighting circuit control switch and for energizing the circuit through another source.

An object of my invention is to provide a simple and effective switch mechanism for the above noted purpose, that may be readily manipulated to any of its operative posltions by applying pressure on one side of an operating handle.

Another object of my invention is to provide a pilot switch of the double throw type '5 that is yieldingly retained in neutral or off position by a cam and follower, and which is actuated to either of its on positions by the follower and with a snap act-ion.

A further object of my invention is to provide a pilot switch that comprises a minimum number of parts that are inexpensive to manufacture, and which may be readily assembled as a unit and ap lied to the switchboard asa separate remova le unit.

These and other objects of my invention will be made apparent throughout the further description of my invention by means of the pilot switch hereinafter described and illustrated in the accompanying drawings, wherein,

Figure 1 is an elevational view of a pilot switch embodying features of my inventlon, and

Figure 2 is a top plan view of the switch shown in Figure 1.

Referring to the drawings, the switch comprises an insulating base 3, upon which a sheet metal frame 4 is mounted. The frame comprises a pair of side plates 5 that are joined by integral cross bars 6 through which attaching screws 7 extend for securing the frame to the base.

An insulating carrier block 8 is pivotally mounted for rotation about the shaft 9 and is disposed between the plates 5 of the frame. The block is provided with integral insulating lateral extensions 10 upon which two pairs of switch blades 11 are secured by means of stud bolts 12. The se arate blades of each bar are spaced apart y insulating washers 13 and the blades are adapted to engage opposite sides of stationary knife blade contacts 14,15 and 16 that are attached to the insulating base 3, the blades 16 being disposed midway between the blades 14 and 15 and so disposed that the contact wings of the switch blades 11 connect the contact blades 16 with either of the contact blades 14 and 15, depending upon the position of the switch blades. The insulating block 8 is provlded with an operatin handle 17 and the inner edge of the block is provided with two inclined convergin cam surfaces 18 and 19 The inner edge 0 the insulatin block 8 is also rovided with a notch 21 disposed between t e inclined surfaces 18 and 19.

A cam follower arm 22 is pivotally mounted between the frame plates 5 for ro-- tatlon about a shaft 23 and the follower is provided with a roller 24. journalled on a shaft 25 mounted on the follower. A spring 26 is disposed between the plates 5 of the frame and engages the free end of the follower 22 and serves to yieldingly press the roll 24 into engagement with the cam surface on the insulating block 8. As shown in Figure 1, the roller is positioned in the notch or depression 21 of the cam surface and serves to yieldingly retain the insulating block or carrier in the neutral position 80 wherein the switch blades 11 are maintained out of contact'with the knife blade contacts 14, 15 and 16.

Assuming that'the lighting circuit is normally maintained by connecting the contacts Hand 16, the circuit is established by forcmg the o eratin handle 17 downward with .the open and, t ereby permitting the roller to force the switch to the desired closed position without interference of the operators hand when the roller en ages the inclined surface 18 of the cam. on it is desired to connect the li hting circuit to the feed conductor through a circuit other than that contaming the usual control or pro-selective mechanism, the switch handle 17 is moved to its uppermost position wherein the switch blades 11 connect the contact blades 15 and 16. By reason of the inclined surfaces of the cam and the notch provided therein, the 10 opening and closing movement of the switch is accomplished with a snap action.

While I have disclosed the invention as being applicable to theater lightin switchboards, it is obvious that the switc may be used as a double throw switch in many different applications.

While I have illustrated but one embodiment of my invention, it will be apparent to those skilled in the art that various changes, 11

modifications, substitutions, additions and omissions may be made in the apparatus illustrated without departing from the s irit and scope of my invention, as set fort in the appended claims.

I claim as my invention:

1. A switch mechanism comprising a pair of spaced frame members having openings therein, an insulating carrier block pivotally mounted on and between the frame members and having integral lateral extensions projecting through the said openings, switch members mounted on the extensions, contact members for engaging the switch members, a. cam integral with the carrier, and a- 01- lower pivotally mounted between the frame members for engaging the said cam and for yieldingly retaining the carrier in predetermined positions.

2. A switch mechansm comprising a pair of spaced frame members having openings therein, an insulating carrier block pivotally mounted on and between the frame menn bers and having integral lateral extensions projecting through the said openings, switch members mounted on the extensions,-contact members for engaging the switch members, a cam integral with the carrier, a follower givotally mounted between the frame memers for engaging the said cam and for yieldingly retaining the carrier in predetermined positions, and a s ring disposed between the frame members or yieldingly pressing the follower into engagement with the said cam.

In testimony whereof, I have hereunto subscribed my name this 3rd day of August,

VICTOR L. BELL. 

